Possible Involvement of Endothelin Peptides and L-Arginine-Nitric Oxide Pathway on the Effect of Endotoxin in the Rabbit Isolated Perfused Kidney

摘要

Escherichia coli endotoxin (LPS) when infused through the renalartery of the rabbit isolated perfused kidney prepared as constantpressure mode, caused a decrease in flow rate and kidney weightindicating its primary vasoconstrictor effect. This effect waspredominant in kidneys from rabbits pretreated with LPS. Endothelin-1at a concentration of 10−10 M and big endothelin-1 at a concentrationof 10−8 M produced equal vasoconstrictor effects in kidney. Additionof endotheHn converting enzyme inhibitor, phosphoramidon, to theperfusion medium at a concentration of 10−6 M caused a reduction inthe effects of both LPS and big ET-1 without altering thevasoconstrictor effect of ETol. However, addition of methylene blue(10−5 M), a soluble guanylate cyclase inhibitor andNG-nitro-L-arginine-methyl ester (10−6 M) to the perfusion mediumcaused a potentiation in the vasoconstrictor effect of LPS.Indomethacin at a concentration of 10−6 M did not alter the effect ofLPS. These results were taken as evidence for the participation ofendothelin peptides and the L-arginine-nitric oxide pathway in theeffect ofLPS in rabbit isolated perfused kidney.